Method and device for sending synchronization information of node and node
Technical Field
The present invention relates to the field of communications technologies, and in particular, to a method and an apparatus for sending synchronization information of a node, and a node.
Background
In LTE D2D (Long Term Evolution Device-to-Device), only 2 synchronization subframes are used to support synchronization sequence SLSS (Sidelink synchronization Signal) and synchronization configuration information of nodes inside, partially, and outside the coverage.
In general, an in-coverage node receives system broadcast information SIB18, acquires a synchronization transmission timing and an slss (system synchronization signal) id, and synchronization information of all UEs (User Equipment) in the same cell in coverage is the same. The outer node of the coverage selects a subframe for transmitting SLSS according to a preconfigured parameter syncOffsndicator 1 (synchronous compensation indication 1) or syncOffsndicator 2 (synchronous compensation indication 2).
Wherein, the coverage of external nodes is divided into the following cases:
1) and partial coverage node: taking an in-coverage node as a reference UE, and sending a synchronous subframe different from the received in-coverage reference UE;
2) the covering outer node refers to the UE as a partial covering node: the method comprises the steps that a part of coverage nodes are used as reference UE, and a sending synchronization subframe is different from the received part of coverage reference UE;
3) the out-of-coverage node reference UE is not a partial coverage node: sending a synchronous subframe different from the received covered reference UE by the covered external node without referring to the UE;
4) independent synchronization sources: no UE is selected as a reference UE, and 1 is randomly selected as a transmission synchronization subframe among 2 synchronization subframes which are preconfigured.
In LTE D2D, an eNB (eNodeB, evolved Node B is abbreviated as "base station name in LTE") configures a transmission subframe for a Node covering the same cell through system information, and occupies 1 same synchronization subframe to transmit synchronization information. In consideration of half-duplex problem, the transceiving node cannot transmit in the same subframe, so that when the R12D2D system is preconfigured, 2 synchronization subframes are set. As fig. 1 shows an example of a configuration of 2 synchronization subframes in an LTE D2D system, a synchronization Subframe 1(Subframe1) is used for transmitting synchronization information of nodes in coverage and nodes out of coverage, and a synchronization Subframe 2(Subframe2) is used for transmitting synchronization information of nodes in partial coverage.
In an LTE V2X (vehicle to vehicle and vehicle to Device, short for Device) system, since a vehicle node has the capability of directly receiving GNSS signals, the vehicle node directly obtaining the GNSS signals can be used as a synchronization source to transmit SLSS and synchronization configuration information. It should be noted that there are 2 synchronization priority processing methods in the LTE V2X system:
1. based on the synchronization of GNSS (Global Navigation Satellite System) or GNSS-equivalent (equivalent to Global Navigation Satellite System), the synchronization priority is from high to low;
priority1 (level 1): GNSS signal 0-hop transmission: obtaining synchronization directly from a GNSS or GNSS-equivalent;
priority2 (level 2): GNSS signal 1 hop transmission: synchronization cannot be directly obtained from the GNSS or the GNSS-equivalent, and synchronization is obtained from a node which directly obtains the GNSS or the GNSS-equivalent synchronization;
priority3 (level 3): other situations.
2. Based on synchronization of eNB, the nodes have 4 priorities which are arranged according to the priorities:
priority1a (level 1 a): UE synchronized with eNB within coverage;
priority1 (level 1): outside coverage, directly obtaining synchronized UE from GNSS or GNSS-equivalent;
priority2 (level 2): synchronization cannot be directly obtained from GNSS or GNSS-equivalent outside the coverage, and synchronization is obtained from a node which directly obtains the GNSS or GNSS-equivalent synchronization;
priority3 (level 3): other situations.
For synchronization based on GNSS or GNSS-equivalent, if a new synchronization subframe is not added, 2 synchronization subframes are still used, which may have a problem, as shown in fig. 2, both a node C covering an intra-synchronization level 3 and a node D partially covering a (Partialcoverage) synchronization level 3 can only select a synchronization subframe1, and due to half-duplex limitation, in this case, both the node C covering the intra-synchronization level 3 and the node D partially covering the synchronization level 3 are in a transmission state, and thus, communication between nodes cannot listen to each other.
For eNB-based synchronization, nodes between the following different synchronization priorities cannot transmit in the same subframe due to half-duplex limitations:
priority1a and Priority1, 2, 3 nodes;
priority1 and Priority 2;
priority2 and Priority 3;
if only 2 subframes are used, assuming that the Priority1a node transmits in the synchronization subframe1 and the Priority1 transmits in the synchronization subframe2, the Priority2 node can only transmit in the synchronization subframe1, resulting in the failure of the Priority2 node to receive the synchronization signal of Priority1 a.
Also, as shown in fig. 3, the synchronization Priority between the partially covered node B of which the synchronization reference UE is Priority1a and the node C of which the synchronization reference UE is Priority2 is Priority3, but the node B and the node C cannot hear each other in communication due to the half duplex limitation.
Disclosure of Invention
The technical problem to be solved by the present invention is to provide a method, an apparatus and a node for sending synchronization information of a node, so as to solve the problem that in an LTE V2X system, due to the limitation of half duplex, the existing synchronization subframe configuration method cannot hear each other and communicate between nodes at the same level.
In order to solve the above technical problem, an embodiment of the present invention provides a method for sending synchronization information of a node, including:
the first receiving node with the priority receives the synchronization information sent by the sending node with the priority through the first synchronization subframe;
the first receiving node acquires configuration information configured for the first receiving node in advance, wherein the configuration information comprises: the first receiving node may send synchronization information to control information of at least one second receiving node in a preset system;
and the first receiving node sends the synchronous information to at least one second receiving node through a second synchronous subframe according to the control information.
Further, the priority of the sending node is greater than or equal to the priority of the first receiving node, and the priority of the first receiving node is greater than or equal to the priority of the second receiving node.
Further, the control information includes: a second sending period of the first receiving node sending the synchronization information and sending sequence control information between the first receiving node and at least one second receiving node having the same priority as the first receiving node; wherein,
the second transmission period of the first receiving node is equal to N times of the first transmission period of the transmitting node, where N is an integer greater than or equal to 1.
Further, the step in which the first receiving node sends synchronization information to at least one second receiving node through a second synchronization subframe according to the control information includes:
and the first receiving node transmits the synchronization information to at least one second receiving node through the second synchronization subframe according to the second transmission period and the transmission sequence control information.
Further, the transmission sequence control information of the synchronization information transmitted by the first receiving node is different from the transmission sequence control information of the synchronization information transmitted by the at least one second receiving node.
Further, the control information includes: and sending a third synchronization subframe of the synchronization information of the nodes in the preset system.
Further, the third synchronization subframe is used to send synchronization information of other nodes except the first receiving node, the second receiving node, and the sending node in the preset system, and the third synchronization subframe is used to send synchronization information of a node with a preset priority in other nodes.
Further, the first, second, and third synchronization subframes are different synchronization subframes from each other.
Further, the preset system further comprises: other nodes than the transmitting node and the first and second receiving nodes, the other nodes having a priority greater than that of the transmitting node.
Further, the other nodes comprise a plurality of nodes, and the plurality of nodes have the same priority; or
The other nodes include a plurality of nodes having a first priority and a plurality of nodes having a second priority, and the first priority is greater than the second priority, which is greater than the priority of the transmitting node.
An embodiment of the present invention provides a device for sending synchronization information of a node, including:
a receiving module, configured to receive, for a first receiving node with a priority, synchronization information sent by a sending node with the priority through a first synchronization subframe;
an obtaining module, configured to obtain, for the first receiving node, configuration information configured for the first receiving node in advance, where the configuration information includes: the first receiving node may send synchronization information to control information of at least one second receiving node in a preset system;
and the sending module is used for sending the synchronization information to at least one second receiving node through a second synchronization subframe for the first receiving node according to the control information.
Further, the priority of the sending node is greater than or equal to the priority of the first receiving node, and the priority of the first receiving node is greater than or equal to the priority of the second receiving node.
Further, the control information includes: a second sending period of the first receiving node sending the synchronization information and sending sequence control information between the first receiving node and at least one second receiving node having the same priority as the first receiving node; wherein,
the second transmission period of the first receiving node is equal to N times of the first transmission period of the transmitting node, where N is an integer greater than or equal to 1.
Further, the sending module is specifically configured to:
and sending the synchronization information to at least one second receiving node through the second synchronization subframe for the first receiving node according to the second sending period and the sending sequence control information.
Further, the transmission sequence control information of the synchronization information transmitted by the first receiving node is different from the transmission sequence control information of the synchronization information transmitted by the at least one second receiving node.
Further, the control information includes: and sending a third synchronization subframe of the synchronization information of the nodes in the preset system.
Further, the third synchronization subframe is used to send synchronization information of other nodes except the first receiving node, the second receiving node, and the sending node in the preset system, and the third synchronization subframe is used to send synchronization information of a node with a preset priority in other nodes.
Further, the first, second, and third synchronization subframes are different synchronization subframes from each other.
Further, the preset system further comprises: other nodes than the transmitting node and the first and second receiving nodes, the other nodes having a priority greater than that of the transmitting node.
Further, the other nodes comprise a plurality of nodes, and the plurality of nodes have the same priority; or
The other nodes include a plurality of nodes having a first priority and a plurality of nodes having a second priority, and the first priority is greater than the second priority, which is greater than the priority of the transmitting node.
An embodiment of the present invention provides a node, including:
a processor; and the memory is connected with the processor through a bus interface, the memory is used for storing programs and data used by the processor in executing operation, and when the processor calls and executes the programs and data stored in the memory, the following functional modules are realized:
a receiving module, configured to receive, for a first receiving node with a priority, synchronization information sent by a sending node with the priority through a first synchronization subframe;
an obtaining module, configured to obtain, for the first receiving node, configuration information configured for the first receiving node in advance, where the configuration information includes: the first receiving node may send synchronization information to control information of at least one second receiving node in a preset system;
and the sending module is used for sending the synchronization information to at least one second receiving node through a second synchronization subframe for the first receiving node according to the control information.
The invention has the beneficial effects that:
according to the scheme, the receiving node selects the proper synchronous subframe to transmit the synchronous information according to the transmitting condition of the transmitting node, the problem that mutual listening communication cannot be realized among nodes of the same level is avoided as much as possible, and the reliability of node communication in the system is improved.
Drawings
Fig. 1 shows a schematic diagram of a synchronization subframe configuration in a conventional LTE D2D system;
FIG. 2 is a diagram illustrating a conventional GNSS synchronization-based synchronization subframe configuration;
fig. 3 is a diagram illustrating a conventional eNB synchronization-based synchronization subframe configuration;
fig. 4 is a flowchart illustrating a method for sending synchronization information of a node according to a first embodiment of the present invention;
fig. 5 is a flowchart illustrating a method for sending synchronization information of a node according to a second embodiment of the present invention;
FIG. 6 is a diagram illustrating a GNSS synchronization-based synchronized subframe configuration using the method of the second embodiment;
fig. 7 is a schematic diagram illustrating eNB synchronization-based synchronization subframe configuration by using the method according to the second embodiment;
FIG. 8 is a diagram illustrating a GNSS synchronization-based synchronized subframe configuration using the method of the third embodiment;
fig. 9 is a schematic diagram illustrating eNB synchronization-based synchronization subframe configuration by using the method according to the third embodiment;
fig. 10 is a block diagram of a transmitting apparatus according to a fourth embodiment of the present invention;
fig. 11 is a schematic structural diagram of a node according to the fifth embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to the accompanying drawings and specific embodiments.
The invention provides a method, a device and a node for transmitting synchronization information of a node, aiming at the problem that the existing synchronous subframe configuration mode cannot hear communication among nodes in the same level due to the limitation of half duplex in the existing LTE V2X system.
Example one
As shown in fig. 4, a method for sending synchronization information of a node according to a first embodiment of the present invention includes:
step 41, the first receiving node with priority receives the synchronization signal sent by the sending node with priority through the first synchronization subframe;
it should be noted that the sending node is a reference UE of the first receiving node, that is, the first receiving node determines a synchronization subframe for sending synchronization information by itself with reference to the received synchronization information of the reference node. In this embodiment, the priority of the sending node is greater than or equal to the priority of the first receiving node.
Step 42, the first receiving node obtains the configuration information configured for it in advance;
it should be noted that the configuration information includes: the first receiving node may send synchronization information to control information of at least one second receiving node in a preset system;
wherein, the preset system is an LTE V2X system.
And 43, the first receiving node sends synchronization information to at least one second receiving node through a second synchronization subframe according to the control information.
It should be noted that the priority of the first receiving node is greater than or equal to the priority of the second receiving node. And in order to ensure that normal communication can be carried out between the first receiving node and the sending node, the second synchronous subframe and the first synchronous subframe are different synchronous subframes.
In this embodiment, the first receiving node is a node of level 3 in the LTE V2X system, the transmitting node is a node of level 2, and the second receiving node is a node of level 3, and the first receiving node can transmit its own synchronization signal to the second receiving node having the same level as the first receiving node by using the configuration of the synchronization subframe of the first receiving node, so that the first receiving node and the node having the same level can listen to each other for communication, thereby improving the reliability of system communication.
Example two
As shown in fig. 5, a method for sending synchronization information of a node according to a second embodiment of the present invention includes:
step 41, the first receiving node with priority receives the synchronization information sent by the sending node with priority through the first synchronization subframe;
it should be noted that the priority of the sending node is greater than or equal to the priority of the first receiving node, and the sending node is a reference UE of the first receiving node.
Step 42, the first receiving node obtains configuration information configured for it in advance, where the configuration information includes: the first receiving node may send a synchronization signal to control information of at least one second receiving node in a preset system;
specifically, the control information includes: a second sending period of the first receiving node sending the synchronization information and sending sequence control information between the first receiving node and at least one second receiving node having the same priority as the first receiving node; wherein,
the second transmission period of the first receiving node is equal to N times of the first transmission period of the transmitting node, where N is an integer greater than or equal to 1.
It should be noted that, nodes of different levels respectively send synchronization signals in respective periods, and in order to facilitate control of sending periods, a sending period of a sending node with the highest priority is usually used as an original synchronization period used in the prior art, and a sending period of a node with a priority lower than that of the sending node is a synchronization period of a preset number; for example, the transmission cycle of the node with the highest priority is the synchronization cycle, and the transmission cycle of the node lower than the highest priority by one level is: a × synchronization period, and the transmission periods of nodes two levels lower than the highest priority are: b is multiplied by a synchronous period, wherein a is more than or equal to b, and a and b are integers which are more than 1 for the convenience of counting the sending period.
And 431, the first receiving node sends the synchronization information to at least one second receiving node through the second synchronization subframe according to the second sending period and the sending sequence control information.
It should be noted that, in order to ensure that the first receiving node and at least one second receiving node having the same level as the first receiving node can implement overhearing communication, the transmission sequence control information of the synchronization signal transmitted by the first receiving node is different from the transmission sequence control information of the synchronization signal transmitted by the at least one second receiving node.
It should be noted that, the sending control information here may be a specific sending time of each node in a sending period, for example, the sending periods of the node 1 and the node 2 are the same, the node 1 sends the synchronization information at the first time of the sending period, and the node 2 sends the synchronization information at the last time of the sending period; by controlling the sending time in the sending period, the nodes with the same grade can send synchronous signals at different moments, and mutual listening communication among different nodes is realized.
It should be noted that, because there are two synchronization priority processing manners in the LTE V2X system, the preset system in this embodiment further includes: other nodes than the transmitting node and the first and second receiving nodes, the other nodes having a priority greater than that of the transmitting node.
Specifically, the other nodes include a plurality of nodes having the same Priority (indicating that Priority processing modes based on GNSS or GNSS-Priority synchronization in the lte v2X system include 3 Priority levels, which are Priority1, Priority2, and Priority3 in sequence from high to low); or
The other nodes include a plurality of nodes having a first Priority and a plurality of nodes having a second Priority, where the first Priority is greater than the second Priority, and the second Priority is greater than the Priority of the transmitting node (indicating that the Priority handling manner based on eNB synchronization in the LTE V2X system includes 4 Priority levels, which are Priority1a, Priority1, Priority2, and Priority3 in order from high to low).
It should be noted that, the main implementation manner of the present embodiment is: according to the sequence of the synchronization priority levels, different sending synchronization intervals based on the synchronization periods with different priority levels are set, the randomness of the time for sending the synchronization information by the nodes with different priority levels is increased, and the possibility of mutual listening among the nodes is increased.
The following describes the configuration of the synchronization subframes based on different synchronization priority processing modes on the node specifically according to the method described in this embodiment.
One, based on GNSS or GNSS-equivalent synchronization
The synchronization subframe used by the node for transmitting the synchronization signal comprises: subframe1 (synchronization Subframe1) and Subframe2 (synchronization Subframe2), and the synchronization subframes of nodes with different synchronization priorities are configured in the following way:
1. priority1 node
Randomly selecting one of the synchronous subframe1 and the synchronous subframe2 for sending the synchronous information, and sending the synchronous information in each synchronous period, wherein the sending period of the Priority1 node is equal to the synchronous period;
2. priority2 node
Selecting a synchronous subframe different from a synchronous subframe where the synchronous information of the synchronous reference UE is located as a synchronous subframe of the Priority2 node;
sending every m synchronization periods, wherein m is an integer greater than 1, namely the node sending period of Priority2 is equal to m multiplied by the synchronization period;
3. priority3 node
All Priority3 nodes send synchronization information every n synchronization cycles, n is an integer greater than 1, and n > is m, namely the Priority3 node sending cycle is equal to n multiplied by the synchronization cycle;
the synchronized subframe configuration is divided into the following cases:
when the synchronization reference UE of the Priority3 node is the Priority2 and Priority3 nodes, selecting a synchronization subframe different from the synchronization subframe where the synchronization information of the synchronization reference UE is located as the synchronization subframe where the Priority3 node sends the synchronization information;
when the node of Priority3 is an independent synchronization source: randomly selecting 1 subframe as a synchronous subframe from the synchronous subframe1 and the synchronous subframe 2;
in the above configuration of the synchronization subframes of the nodes, when the transmission period of a node is greater than the synchronization period, 1 synchronization subframe is randomly selected from a plurality of synchronization periods of the transmission period as the transmission synchronization period of the node, and the synchronization subframe adapted to the node is selected in the transmission synchronization period to transmit the synchronization information, that is, the synchronization information of different nodes in the same level has different transmission orders.
As shown in fig. 6, in practical application, after the nodes based on GNSS or GNSS-equivalent synchronization (assuming that the synchronization period is 50ms) perform synchronization subframe configuration according to the method of the present embodiment, the configuration condition of each node is specifically as follows:
a1, in-coverage and out-of-coverage Priority1 nodes a and E are the highest Priority, sent 50ms per synchronization period, and sent in synchronization subframe 1.
A2, in-coverage and out-of-coverage Priority2 nodes B and F, where the synchronization reference UE is nodes a and E of Priority1, and the synchronization subframe must be different from Priority1 nodes a and E, and the synchronization subframe2 is selected to be transmitted, where the transmission period is 2 synchronization periods, that is, 2 × 50 is 100 ms; and the in-coverage Priority2 node B randomly selects the synchronization subframe2 50ms (Index 1) after the 100ms synchronization interval to transmit; out-of-coverage Priority2 node F randomly selects the first 50ms (Index is 0) of the 100ms synchronization interval to transmit, i.e. node F transmits the synchronization information before node B.
A3, an in-coverage Priority3 node C, where the synchronization reference UE is a node B with an in-coverage Priority2, the synchronization subframe must be different from the in-coverage Priority2 node B, and a synchronization subframe1 is selected to be transmitted, where a transmission period is 4 synchronization periods, that is, 4 × 50 ═ 200 ms; the node C randomly transmits synchronization information in the 1 st 50ms (Index 0) synchronization subframe1 of 200 ms.
A4, and out-of-coverage Priority3 nodes D and G, where the synchronization reference UE is a node F of out-of-coverage Priority2, and the synchronization subframe must be different from the out-of-coverage Priority2 node F, and a synchronization subframe1 is selected to be transmitted, where a transmission period is 4 synchronization periods, that is, 4 × 50 is 200 ms; receiving nodes D and G of 2 priorities 3 randomly select synchronization sub-frame 1 of 2 nd 50ms (Index ═ 1) and 3 rd 50ms (Index ═ 2) of 200ms to transmit synchronization information, respectively.
A5, the independent synchronization source node H outside the coverage randomly selects a synchronization subframe2 as a transmission synchronization subframe, and the transmission period is 4 synchronization periods, that is, 4 × 50 ═ 200 ms; node H randomly transmits at 2 nd 50ms (Index 1) sync subframe2 of 200 ms.
A6, the out-of-coverage Priority3 node I receives the synchronization information sent by the independent synchronization source Priority3 node H and the synchronization subframe 1Priority3 node G at the 3 rd 50ms (Index ═ 2), if the out-of-coverage Priority3 node I selects the independent synchronization source node H as the synchronization reference UE, the synchronization information is sent by using the synchronization subframe1, and the sending period is 4 synchronization periods, that is, 4 × 50 ═ 200 ms; node I randomly selects 200ms 4 th 50ms (Index 3) synchronization subframe1 to transmit synchronization information.
Based on eNB synchronization
The synchronization subframe used by the node for transmitting the synchronization signal comprises: the synchronization subframe1 and the synchronization subframe2 are configured in the following way, wherein the synchronization subframes of the nodes with different synchronization priorities are configured as follows:
1. node of Priority1 a:
configuring according to the system information of the eNB, which may be a synchronization subframe1 or a synchronization subframe2, and sending synchronization information in each synchronization period, that is, the sending period of the node of Priority1a is equal to the synchronization period;
2、Priority 1:
if the Priority1 node has the synchronous reference UE with the Priority1a, selecting a synchronous subframe different from the synchronous subframe where the synchronous information of the synchronous reference UE is located as the synchronous subframe of the Priority1 node; otherwise, randomly selecting 1 subframe from the synchronous subframe1 or the synchronous subframe2 as a synchronous subframe;
sending every X synchronous periods, wherein X is an integer greater than 1, namely the node sending period of Priority1 is equal to X multiplied by the synchronous period;
3、Priority 2:
selecting a synchronous subframe different from a synchronous subframe where the synchronous information of the synchronous reference UE is located as a synchronous subframe of the Priority2 node;
transmitting every Y synchronization periods, wherein Y is an integer greater than 1, and Y > -X, namely the node transmission period of Priority2 is equal to Y multiplied by the synchronization period;
4、Priority 3:
all Priority3 nodes send synchronization information every Z synchronization periods, Z is an integer greater than 1, and Z > -Y, namely the Priority3 node sending period is equal to Z multiplied by the synchronization period;
the synchronized subframe configuration is divided into the following cases:
when the synchronization reference node of the Priority3 node is the Priority1a, Priority2 and Priority3 nodes, selecting a synchronization subframe different from the synchronization subframe where the synchronization information of the synchronization reference UE is located as the synchronization subframe of the Priority3 node;
when the Priority3 node is an independent synchronization source: randomly selecting 1 subframe as a synchronous subframe from 2 synchronous subframes;
in the above configuration of the synchronization subframes of the nodes, when the transmission period of a node is greater than the synchronization period, 1 synchronization subframe is randomly selected from a plurality of synchronization periods of the transmission period as the transmission synchronization period of the node, and the synchronization subframe adapted to the node is selected in the transmission synchronization period to transmit the synchronization information, that is, the synchronization information of different nodes in the same level has different transmission orders.
As shown in fig. 7, in practical application, after the nodes based on eNB synchronization (assuming that the synchronization period is 50ms) perform synchronization subframe configuration according to the method of this embodiment, the configuration situation of each node is specifically as follows:
the synchronous subframe configuration situation of each node is as follows:
b1, in-coverage Priority1a node a is the highest Priority, and transmits every 50ms synchronization period, assuming transmission in synchronization subframe 1.
B2, the out-of-coverage Priority1 node E is the highest Priority out of coverage, when the synchronization reference UE is Priority1a, the synchronization subframe must be different from the in-coverage Priority1a node a, the synchronization subframe2 is selected to be transmitted, the transmission period is 2 synchronization periods, i.e. 2 × 50 equals 100ms, and the synchronization subframe2 at the last 50ms (Index equals 1) of the 100ms synchronization interval is randomly selected to be transmitted;
b3, the out-of-coverage Priority2 node F, where the synchronization reference UE is the node E of the out-of-coverage Priority1, the synchronization subframe must be different from the out-of-coverage Priority1 node E, and the synchronization subframe1 is selected to be transmitted, where the transmission period is 4 synchronization periods, that is, 4 × 50 is 200 ms. The out-of-coverage Priority2 node F randomly selects the 1 st 50ms (Index is 0) synchronization subframe1 at the 200ms synchronization interval to transmit;
b4, out-of-coverage Priority3 node G, synchronization reference UE is node F of out-of-coverage Priority2, the synchronization subframe must be different from the out-of-coverage Priority2 node F, and the synchronization subframe2 is selected to be transmitted, where the transmission period is 6 synchronization periods, that is, 6 × 50 is 300 ms. Receiving nodes C and G of 2 priorities 3 transmit randomly in synchronization sub-frame 2 of 2 nd 50ms (Index 1) and 3 rd 50ms (Index 2) of 300ms, respectively, that is, the synchronization information of node C is transmitted before node G.
B5, the independent synchronization source node H outside the coverage randomly selects the subframe1 as a transmission synchronization subframe, where the transmission period is 6 synchronization periods, that is, 6 × 50 ═ 300 ms; node H randomly selects 1 st 50ms (Index 0) sync subframe1 at 300ms for transmission.
B6, the out-of-coverage Priority3 node D receives the independent synchronization source Priority3 node H and the synchronization information sent by the nodes C and G at the 3 rd 50ms (Index ═ 2) subframe 2Priority3, the out-of-coverage Priority3 node D selects the independent synchronization source H as the synchronization reference UE, then the synchronization subframe is sent as 2, and the sending period is 6 synchronization periods, that is, 6 × 50 ═ 300 ms; node D randomly selects the 5 th 50ms (Index 4) synchronization subframe2 of 300ms for transmission.
It should be noted that, by using this configuration mode of node synchronization subframes, the problem that the nodes at the same level cannot listen to each other for communication is solved, and the reliability of system communication is improved.
EXAMPLE III
Continuing with fig. 4, a sending method of synchronization information of a node according to a third embodiment of the present invention includes:
step 41, the first receiving node with priority receives the synchronization signal sent by the sending node with priority through the first synchronization subframe;
it should be noted that the priority of the sending node is greater than or equal to the priority of the first receiving node, and the sending node is a reference UE of the first receiving node.
Step 42, the first receiving node obtains the configuration information configured for it in advance;
it should be noted that the configuration information includes: the first receiving node may send synchronization information to control information of at least one second receiving node in a preset system;
the control information includes: and sending a third synchronization subframe of the synchronization information of the nodes in the preset system.
And 43, the first receiving node sends synchronization information to at least one second receiving node through a second synchronization subframe according to the control information.
It should be noted that the first synchronization subframe, the second synchronization subframe, and the third synchronization subframe are synchronization subframes that are different from each other.
In this embodiment, three synchronization subframes are used to perform transmission control of synchronization information of nodes in the LTE V2X system, so that the problem that the nodes cannot listen to each other for communication because multiple nodes use the same synchronization subframe to perform transmission of synchronization information is effectively solved.
Because the nodes in the LTE V2X system have multiple priority levels, in order to facilitate the allocation of the synchronization subframes, the third synchronization subframe is specifically used to send synchronization information of other nodes except the first receiving node, the second receiving node, and the sending node in the preset system, and the third synchronization subframe is used to send synchronization information of nodes with preset priority levels in other nodes.
In addition, because there are two synchronization priority processing manners in the LTE V2X system, the preset system in this embodiment further includes: other nodes than the transmitting node and the first and second receiving nodes, the other nodes having a priority greater than that of the transmitting node.
Specifically, the other nodes include multiple nodes having the same Priority (indicating that a Priority processing manner based on GNSS or GNSS-equivalent synchronization in the lte v2X system includes 3 Priority levels, which are Priority1, Priority2, and Priority3 in sequence from high to low, where a newly added third synchronization subframe is used to transmit synchronization information of which the node is Priority 1); or
The other nodes include a plurality of nodes with a first Priority and a plurality of nodes with a second Priority, where the first Priority is greater than the second Priority, and the second Priority is greater than the Priority of the sending node (indicating that the Priority processing mode based on eNB synchronization in the LTE V2X system includes 4 Priority levels, which are Priority1a, Priority1, Priority2, and Priority3 in sequence from high to low, where the newly added third synchronization subframe is used for synchronization information of which the sending node is Priority 1).
It should be noted that, the main implementation manner of the present embodiment is: and a synchronization subframe is newly added on the basis of the original synchronization subframe, and the newly added synchronization subframe is used for sending the synchronization information of the nodes with the preset priority.
The following describes the configuration of the synchronization subframes based on different synchronization priority processing manners in detail according to the method of this embodiment.
One, based on GNSS or GNSS-equivalent synchronization
The synchronization subframe used by the node for transmitting the synchronization signal comprises: subframe1 (synchronization Subframe1), Subframe2 (synchronization Subframe2) and newly added Subframe3 (synchronization Subframe 3), and the configuration mode of the synchronization subframes of the nodes with different synchronization priorities is as follows:
1. priority1 node
Transmitting synchronization information on the added synchronization subframe 3;
2. priority2 node
As the synchronization information of Priority1 needs to be received, randomly selecting 1 synchronization subframe from the synchronization subframe1 or the synchronization subframe2 to transmit the synchronization information;
3. priority3 node
If the synchronization reference UE of the Priority3 node is a Priority2 or Priority3 node, randomly selecting 1 subframe as a synchronization subframe to send synchronization information in synchronization subframes 1 or2 and different from the synchronization subframe where the received synchronization information is located;
4. independent synchronization source
And randomly selecting 1 subframe as a synchronous subframe to transmit the synchronous information from the 3 synchronous subframes.
As shown in fig. 8, in practical application, after the nodes based on GNSS or GNSS-equivalent synchronization perform synchronization subframe configuration according to the method of the present embodiment, the configuration condition of each node is specifically as follows:
c1, nodes A and E of Priority1 transmit synchronization information in a synchronization subframe3, a node B covering inside Priority2 transmits in the synchronization subframe1, a node F covering outside Priority2 transmits in the synchronization subframe2, a node C covering inside Priority3 transmits in the synchronization subframe2, and a node D partially covering Priority3 transmits in the synchronization subframe1, so that the nodes C and D which are both Priority3 can listen to each other for communication;
c2, after the Priority3 node G outside the coverage receives the synchronization information of the Priority2 node F and the Priority3 node D, selecting the Priority2 node F as the synchronization reference UE, and then sending the synchronization information by using the synchronization subframe 1.
And C3, randomly selecting the synchronization subframe2 as a transmission synchronization subframe by the independent synchronization source node H outside the coverage, and when the Priority3 node I outside the coverage receives the synchronization information transmitted by the independent synchronization source Priority3 node H and the Priority3 node G in the synchronization subframe2, and selecting the independent synchronization source as the synchronization reference UE by the Priority3 node I outside the coverage, then adopting the synchronization subframe1 to transmit the synchronization information.
Based on eNB synchronization
The synchronization subframe used by the node for transmitting the synchronization signal comprises: the method comprises the following steps that synchronous subframes 1, 2 and a newly added synchronous subframe3 are arranged, and the synchronous subframes of nodes with different synchronous priorities are configured as follows:
1. priority1a node
Configuring according to system information of the eNB, wherein the configuration may be synchronous subframe1 or synchronous subframe 2;
2. priority1 node
Transmitting synchronization information on the added synchronization subframe 3;
3. priority2 node
Selecting 1 subframe from the synchronous subframe1 or the synchronous subframe2 as a synchronous subframe which is different from the synchronous subframe where the received synchronous information is located;
4. priority3 node
If the synchronization reference UE of the Priority3 node is a Priority1a, Priority2, or Priority3 node, randomly selecting 1 subframe as a synchronization subframe from synchronization subframes different from the synchronization subframe in which the received synchronization information is located in synchronization subframe1 or synchronization subframe 2;
5. independent synchronization source
And randomly selecting 1 subframe as a synchronous subframe to transmit the synchronous information from the 3 synchronous subframes.
As shown in fig. 9, in practical application, after the nodes based on eNB synchronization perform synchronization subframe configuration according to the method of this embodiment, the configuration of each node is specifically as follows:
d1, node A with Priority1a only in coverage, sending in synchronization sub-frame 2; the node B partially covering Priority3 selects the node a of Priority1a as the synchronization reference UE, and transmits synchronization information in synchronization subframe 1.
D2, the node E covering the outer Priority1 is sent in the synchronous subframe3, and the node F covering the outer Priority2 is sent in the synchronous subframe 1; after receiving the synchronization information of the Priority3 node B and the Priority2 node F, the out-of-coverage Priority3 node C selects the Priority2 node as the synchronization reference UE, and then adopts the synchronization subframe2 to transmit the synchronization information; and after receiving the synchronization information of the Priority2 node F, the out-of-coverage Priority3 node G adopts the synchronization subframe2 to transmit the synchronization information.
D3, the node D covering the Priority3 receives the synchronization information of the Priority3 in the synchronization subframe2, selects the synchronization subframe1 and transmits the synchronization information.
D4, randomly selecting the subframe2 as a sending synchronization subframe by the independent synchronization source node H outside the coverage, and when the synchronization information sent by the independent synchronization source Priority3 node H and the Priority3 node D in the synchronization subframe1 is received by the Priority3 node I outside the coverage, and the independent synchronization source is selected as the synchronization reference UE by the Priority3 node I outside the coverage, then sending the synchronization information by adopting the synchronization subframe 1.
It should be noted that, in this embodiment, by adding one synchronization subframe, the selectable range of the synchronization subframe between nodes of different levels is increased, the problem that the inter-node communication cannot be heard effectively can be solved, and the reliability of the LTE V2X system communication is improved.
It should be noted that, in the above embodiments of the present invention, two ways are provided to allocate the synchronization subframes for sending synchronization information between nodes, the synchronization subframe allocation way in the second embodiment is the first way, and the synchronization subframe allocation way in the third embodiment is the second way. When the system resource occupancy rate is high and the requirement on the node synchronous convergence is not high, each node in the system can configure synchronous subframes according to the first mode; when the system resource occupancy rate is not high and the requirement on the node synchronization convergence is high, each node in the system can configure the synchronization subframe according to the second mode.
Example four
As shown in fig. 10, an embodiment of the present invention provides an apparatus 100 for sending synchronization information of a node, including:
a receiving module 101, configured to receive, for a first receiving node with a priority, synchronization information sent by a sending node with the priority through a first synchronization subframe;
an obtaining module 102, configured to obtain, for the first receiving node, configuration information configured for the first receiving node in advance, where the configuration information includes: the first receiving node may send synchronization information to control information of at least one second receiving node in a preset system;
a sending module 103, configured to send, to the first receiving node, synchronization information to at least one second receiving node through a second synchronization subframe according to the control information.
Specifically, the priority of the sending node is greater than or equal to the priority of the first receiving node, and the priority of the first receiving node is greater than or equal to the priority of the second receiving node.
Optionally, the control information includes: a second sending period of the first receiving node sending the synchronization information and sending sequence control information between the first receiving node and at least one second receiving node having the same priority as the first receiving node; wherein,
the second transmission period of the first receiving node is equal to N times of the first transmission period of the transmitting node, where N is an integer greater than or equal to 1.
Further, the sending module 103 is specifically configured to:
and sending the synchronization information to at least one second receiving node through the second synchronization subframe for the first receiving node according to the second sending period and the sending sequence control information.
Further, the transmission sequence control information of the synchronization information transmitted by the first receiving node is different from the transmission sequence control information of the synchronization information transmitted by the at least one second receiving node.
Optionally, the control information includes: and sending a third synchronization subframe of the synchronization information of the nodes in the preset system.
Specifically, the third synchronization subframe is used to send synchronization information of other nodes except the first receiving node, the second receiving node, and the sending node in the preset system, and the third synchronization subframe is used to send synchronization information of a node with a preset priority in other nodes.
Further, the first, second, and third synchronization subframes are different synchronization subframes from each other.
Further, the preset system further comprises: other nodes than the transmitting node and the first and second receiving nodes, the other nodes having a priority greater than that of the transmitting node.
Further, the other nodes comprise a plurality of nodes, and the plurality of nodes have the same priority; or
The other nodes include a plurality of nodes having a first priority and a plurality of nodes having a second priority, and the first priority is greater than the second priority, which is greater than the priority of the transmitting node.
It should be noted that the embodiment of the transmission apparatus is a one-to-one correspondence transmission apparatus to the above-mentioned transmission method embodiments, and all the implementation manners in the above-mentioned transmission method embodiments are applied to the embodiment of the transmission apparatus, and the same technical effects can be achieved.
EXAMPLE five
As shown in fig. 11, the present embodiment provides a node including:
a processor 111; and a memory 113 connected to the processor 111 through a bus interface 112, where the memory 113 is used to store programs and data used by the processor 111 when executing operations, and when the processor 111 calls and executes the programs and data stored in the memory 113, the following functional modules are implemented:
a receiving module, configured to receive, for a first receiving node with a priority, synchronization information sent by a sending node with the priority through a first synchronization subframe;
an obtaining module, configured to obtain, for the first receiving node, configuration information configured for the first receiving node in advance, where the configuration information includes: the first receiving node may send synchronization information to control information of at least one second receiving node in a preset system;
and the sending module is used for sending the synchronization information to at least one second receiving node through a second synchronization subframe for the first receiving node according to the control information.
The processor 111 is also configured to implement the functions of any other module of the above-described transmitting apparatus.
Note that, the node in the present embodiment may be a vehicle or a user terminal belonging to the LTE V2X system, or may be a device used for constructing the LTE V2X system.
Those skilled in the art will appreciate that all or part of the steps for implementing the above embodiments may be performed by hardware, or may be instructed to be performed by associated hardware by a computer program that includes instructions for performing some or all of the steps of the above methods; and the computer program may be stored in a readable storage medium, which may be any form of storage medium.
While the preferred embodiments of the present invention have been described, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.